In explicit status checking, shown at 9 in Figure 3-1, you
explicitly examine an SQLCA field for a particular value, then
perform an operation depending on the field's value.  In this
example the SQLCA field named SQLCode is examined to determine
whether it contains a value of:
 0, indicating no error occurred.
 100, indicating no rows qualified for the SELECT operation.
 -10002, indicating more than one row qualified for the SELECT
operation.
If SQLCode contains any other value, subprogram unit
SQLStatusCheck is executed.  Values with greater negative
values than -14024 indicate errors serious enough to warrant
terminating the program.